It has become increasingly desirable to improve cooling systems in aerospace applications. Typically, cooling systems provide air conditioning, refrigeration and freezer services, and the like for commercial and other aerospace systems. In general, various known options are available for providing cooling, but such options have drawbacks that limit the design options for aerospace applications.
To accommodate the wide range of possible ambient operating conditions of the aircraft, cooling systems for aerospace applications often use a gas-based system. That is, typical cooling systems include a relatively bulky and low efficiency gas-based system in order to cover the range of conditions that can be experienced during aircraft operation. Such systems include an ability to reject heat during operation to complete the thermodynamic cycle. However, some aircraft operate at above Mach 1, or the speed of sound, in which case the ability to reject heat may be limited due to the frictional component that can cause heating of air that may be used to reject heat.
Thus, cooling systems have been developed to provide alternatives for heat rejection during high Mach aircraft operation. One known option uses fuel or thermal storage units for cooling as high Mach heat sinks That is, a fuel or other thermal storage unit may be provided, to which heat may be rejected during operation of an aircraft at high Mach speeds. However, fuel storage units have limited capacity and limited operational time. And, as fuel is consumed, the reservoir to which the heat is rejected is reduced in volume, providing limited options for long duration flights.
Thus, there is a need to improve cooling in aircraft for high Mach operation.